Releasable winding mechanism for sewing machines

ABSTRACT

The winding mechanism is used with sewing machines of the type having a fixedly positioned winder shaft with a bobbin-receiving pin protruding from the machine casing, and a friction wheel for driving the winder shaft and having a friction wheel shaft separated from the winder shaft but operatively connected with the winder shaft and engageable with the driving wheel of the machine to selectively operate the winding mechanism. The inner end of the winder shaft has fixed thereto a disk with a slot extending diametrically thereof, and an end of the friction wheel shaft carries a cooperating disk having a pin or lug engageable in the slot. The friction wheel is mounted on a carrier which is spring biased to an operating position and a rest position. The driving connection between the two shafts is maintained at all times within the range of displacement of the friction wheel shaft between the operating and rest positions.

United States Patent [15] 3,670,974

Ueltschi 1 June 20, 1972 [s41 RELEASABLE WINDING MECHANISM 2,933,4555/1961 Herbst ..242/22 FOR SEWING MACHINES [72] Inventor: OdetteUeltschi, Steckborn, Switzerland [73] Assignee: Fritz Gegauf AGBernina-Nahmaschlnenfabrik, Steckbom, Switzerland [22] Filed: Jan. 21,1971 [21] Appl. No.: 108,517

[30] Foreign Application Priority Data Feb. 6, 1970 Switzerland..1780/70 [52] US. Cl. ..242/22, 112/218 A [51] Int. Cl. ..B65h 54/18,D05b 59/00 [58] Field of Search ..242/54, 20, 22, 23; 112/218 A; 287/2,129, 130; 74/194, 206; 64/8, 10, 31

[56] References Cited UNITED STATES PATENTS 935,263 9/ 1909 Chapelle"242/22 2,148,975 2/1939 Agren 2,836,371 5/1958 Ayres ..242/22 3,581,6876/1971 Meieret al.... ..112/218A Primary Examiner-Stanley N. GilreathAssistant Examiner-Werner H. Schroeder Attorney-John J. McGlew andAlfred E. Page ABSTRACT The winding mechanism is used with sewingmachines of the type having a fixedly positioned winder shaft with abobbinreceiving pin protruding from the machine casing, and a frictionwheel for driving the winder shah and having a friction wheel shaftseparated from the winder shaft but operatively connected with thewinder shaft and engageable with the driving wheel of the machine toselectively operate the winding mechanism. The inner end of the windershaft has fixed thereto a disk with a slot extending diametricallythereof, and an end of the friction wheel shaft carries a cooperatingdisk having a pin or lug engageable in the slot. The friction wheel ismounted on a carrier which is spring biased to an operating position anda rest position. The driving connection between the two shafts ismaintained at all times within the range of displacement of the frictionwheel shaft between the operating and rest positions.

10 Claims, 6 Drawing Figures PATENTEDJUHZO 1972 3,57 ,97

SHEEI 1 BF 3 INVENTOR. ODETTE \IELTS 'L 1 RELEASABLE WINDING MECHANISMFOR SEWING MACHINES BACKGROUND OF THE INVENTION There are known sewingmachine winding mechanisms which are attached to the sewing machine onthat side of the machine arm facing the operator and close to thedriving wheel. As a rule, these winding mechanisms include a winder armwhich can be pivoted in a vertical plane and which serves as a carrierfor the winder shaft which is provided with a friction wheel for drivingthe same. Such winding mechanisms are completely external to the sewingmachine casing, and render the cleaning of the sewing machine difficultas well as considerably impairing the esthetic effect of a modern sewingmachine.

There are also known winding mechanisms, for sewing machines, which arearranged under a hinged cover or which can be swung into the interior ofthe machine casing when not in use so that, in rest position, they arecovered by a cover. However, these winding mechanisms are verycumbersome to operate and, as they require a relatively largemanufacturing apparatus, are consequently expensive.

Other known winding mechanisms for sewing machines are arranged on, thearm cover of the machine, or on the side of the machine facing theoperator. As a rule, these usually comprise a winder arm which can bemoved toward the driving wheel, and which carries the winder shaft withthe friction wheel and the bobbin-receiving pin protruding from thesewing machine casing. These winding mechanisms are spring biased ontheir operating position and in their rest position, and are more andmore preferred in sewing machines. However, the displaceability of thewinder shaft relative to the driving wheel requires a correspondinglarge breakthrough or opening in the sewing machine casing. Apart fromthe fact that the esthetic effect of the sewing machine is impaired, thefuzz or lint formed during the winding of the thread can easily enterthrough the breakthrough into the interior of the sewing machine casing.Due to their arrangement on the sewing machine, these winding mechanismsalso have the disadvantage that the tension of the thread, formed duringwinding of the thread from a supply bobbin to a looper thread bobbin,counteracts the contact pressure of the friction wheel on the drivingwheel and necessary to drive the friction wheel. The contact pressurethus can be reduced to such an extent, under unfavorable circumstances,for example, when unwinding the thread from a large supply bobbin, thatit is no longer sufficient for reliable drive of the friction wheel.

Winding mechanisms with a fixedly positioned but axially displaceablewinder shafts are known and do not have the above-mentioneddisadvantages. However, in these winding mechanisms, thebobbin-receiving journal protrudes from the sewing machine housing inits rest position, with the protrusion increased by the amount of theaxial displacement. In addition, when the winding mechanism isconnected, a locking finger of the lever sensing the amount of woundthread moves over a lug of the winder shaft and thus keeps the shaft inthe connected position. The sensing lever grazes, during the windingprocess, constantly on the lug of the winder shaft, so that annoyingnoises are produced and those parts rubbing against each other arerapidly worn out.

In another known winding mechanism with axially displaceable windershafts, the sensing lever bears against a flange of the thread bobbin tobe wound, and thus keeps the winder shaft in its operating position.This axial limitation of the winder shaft also causes annoying grazingnoises and rapid wear of the parts rubbing against each other. Underunfavorable conditions, for example, with unilateral winding of thethread of the looper thread bobbin, the thread even can be clampedbetween the bobbin flange and the sensing lever hearing against thelatter, and thus can be damaged.

SUMMARY OF THE INVENTION This invention relates to releasable windingmechanisms for sewing machines and, more particularly, to a releasablewinding mechanism of the above-mentioned type and which does not havethe disadvantages of the mentioned known winding mechanisms.

In accordance with the invention, the winding mechanism is characterizedby the fact that the axis of the friction wheel shaft is displaceablelaterally with respect to the axis of the fixedly positioned windershaft, for starting and stopping the winding mechanism, and the drivingconnection between the two shafts is maintained at all times within thedisplacement range of the friction wheel axis necessary for movementbetween the operating position and the rest position.

The winding mechanism embodying the invention is very easy to operate,and fits harmoniously into the outer form or contour of the sewingmachine casing, since the bobbinreceiving pin has to project from thecasing only by the very small height of the sensing lever which isnecessary in any case, and can be covered almost completely by thislever. Since no breakthroughs or openings are required in the sewingmachine casing within the range of the winding mechanism, penetration ofdust and fun or lint into the interior of the easing is effectivelyprevented. Another advantage is that the contact pressure of thefriction wheel on the driving wheel cannot be influenced by the tensionof the thread to be wound.

An object of the invention is to provide an improved releasable windingmechanism for sewing machines.

Another object of the invention is to provide such a releasable windingmechanism in which the esthetic appearance of the sewing machine casingis not impaired and all the parts are disposed within the casing.

A further object of the invention is to provide such a winding mechanismin which there are no uncovered openings in the sewing machine casing,thus preventing entry of dust and lint or the like into the casing.

Another object of the invention is to provide such a winding mechanismwhich is simple in construction, easy to operate, and inexpensive tomanufacture.

For an understanding of the principles of the invention, reference ismade to the following description of a typical embodiment thereof asillustrated in the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING In the drawing:

FIG. 1 is a partial elevation view of a sewing machine with a windingmechanism, embodying the invention, built into the arm cover;

FIG. 2 is a partial top plan view of the sewing machine illustrating thearrangement of the winding mechanism and the course of the thread duringwinding;

FIG. 3 is a sectional view taken along the line I-[ of FIG. 2 andillustrating the winding mechanism in its operating position;

FIG. 4 is a view similar to FIG. 2 but illustrating the windingmechanism in its rest position;

FIG. 5 is a sectional view taken along the line II-II of FIG. 2illustrating the winding mechanism in its operating position; and

FIG. 6 is a top plan view of the winding mechanism with the arm coverpartly cut away and the winder shaft removed.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing, asewing machine is illustrated as having an arm 1 provided with an armcover 2, and as being driven by known driving means, not shown, througha driving wheel 3. Driving wheel 3 is operatively connected, in a knownmanner, with the arm (not shown) of the sewing machine, and can bereleased selectively from such connection, by means of a release screw4, so that driving wheel 3 can rotate on the arm shaft without drivingthe latter. The usual operating or control elements of the sewingmachine are illustrated at 5, 6 and 7.

A winding mechanism 8, embodying the invention, is arranged close todriving wheel 3, in arm cover 2. Thread 9 is unwound from a supplybobbin 11 arranged on a yarn roll holder 10, is conducted around a guidepin 12, which can also be designed as a thread pretensioning means, andis wound on looper thread bobbin 13. Bobbin 13 is arranged on theslotted bobbin-receiving pin 14 of a winder shaft 15 protruding from armcover 2. Winder shaft 15 is freely rotatable in a hub 16 integral witharm cover 2, and is secured against axial displacement by a lug 17 and alocking ring 18. Shaft 15 has a mounting portion 46 at its bottom end,on which there is nonrotatably mounted a driving disk 19 formed with adriving slot 20.

A friction wheel shaft 21 is freely rotatable on a hub 22 of a winderarm 23, and is secured against axial displacement by the hub 24 of afriction wheel 25, hub 24 being pressed on a mounting portion'49 at thebottom of friction wheel shaft 21. Friction wheel 25 is vulcanized, in aknown manner, on hub 24, or is secured thereon in any other way. The topend of friction wheel shaft 21 has a mounting portion 46 on which thereis non-rotatably secured a driving disk 27 provided with a driving pin28 which engages slot of disk 19, thus establishing the drivingconnection between friction wheel shaft 21 and winder shaft 15. Winderarm 23 is pivotally secured with a setscrew'29 on a bearing block 30 ofcover 2, for pivoting in a horizontal plane about the axis of setscrew29, and is biased by a helical tension spring 31 toward driving wheel 3.The other end of spring 31 is secured on a depending bolt 43 screwedinto cover 2.

A lever 32, which senses the amount of thread wound on looper threadbobbin 13, is pivotally secured by a setscrew 33 on release arm 34 forswinging about the axis of screw 33, and is guided in a slot 35 in armcover 2. Release arm 34 is pivotally secured, for swinging in ahorizontal plane, by a setscrew 36 secured to arm cover 2, and its freeend carriesa control pin 37. A leafspring 40 is adjustably mounted onarm cover 2 through the medium of screws 38 and 39, and is formed with astriking ramp 41 and, in the rest position of winding mechanism 8, hasits free end pressing against winder arm23. The force exerted byleafspring 40 is greater than the tension of helical spring 31, so thatleafspring 40 holds winding mechanism 8 in its rest position and out ofengagement with driving wheel 3.

In the operating position of winding mechanism 8, leaf-v spring 40 ispushed away from winder arm 23 by control pin 37 of release arm 34, sothat spring 31 can pull winder arm 23, with friction wheel rotatablymounted therein, toward driving wheel 3, and thus establish theoperating connection between driving wheel 3 and friction wheel 25. Ramp41 of spring 40 serves,'on the one hand, to push leafspring 40 away fromwinder arm 24 during the starting of winding mechanism 8 and, on theother hand, to release winding mechanism 8 by pushing control pin 37,secured on release arm 34, away when looper thread bobbin 13 is full.Slot 42 in leafspring 40 permits an exact adjustment of the releasemoment of the winding mechanism, by loosening and then retightening thetwo screws 38 and 39.

The lateral movement of friction wheel shaft 21 relative to winder shaft15 is so limited by stops 44 and 45, integral with arm cover 2, thatdriving pin 28 of driving disk 27 cannot be disengaged from slot 20 ofdisk 19. Disks 27 and 19 preferably are made of plastic compositionmaterial, and are press fitted on the notched mounting portions 46 and47 of winder shaft 15 and friction wheel shaft 21, respectively.

Winding mechanism 8 normally is in its rest position as illustrated inFIG. 4. In order to supplement the looper thread supply, looper threadbobbin 13 is attached on bobbin-receiving pin 14 of mechanism 8. Theslotted bobbin-receiving pin 14 provides a non-rotational connectionbetween winder shaft 15 and looper thread bobbin 13, since the lightlyspread bobbin-receiving pin 14 is clamped firmly in bore 48 of looperthread bobbin 13. The thread 9, to be wound, is now lead from supplyhohbin 11 around guide pin 12 to bobbin 13, and wound by hand severalturns clockwise around the latter.

To start winding mechanism 8, sensing lever 32 is pushed along slot 35of cover 2 against bobbin 13, and release arm 34 thus is turned aboutthe axis of setscrew 38 toward winder shaft 13. Control pin 37 strikesagainst ramp 41 of leafspring 40 and pushes spring 40 away from winderarm 23, so that winder arm 23 is turned, under the action of helicalspring 31, about the axis of setscrew 20 serving as a pivot, and towarddriving wheel 3 until friction wheel 25 bears against driving wheel 3.During the further rotation of release arm 34, until it bears on sensinglever 32 at the end of slot 35 in arm cover 2, control pin 37 strikesagainst a part of leafspring 40 extending substantially at a right angleto release arm 34. Spring 40 now acts on control pin 37 of release arm34 in a manner such that arm 34, with sensing lever 32 secured thereonand protruding between the flanges of looper thread bobbin 13, issecured by leafspring 40 against accidental displacement.

In this position of winding mechanism 8, which is shown in FIGS. 3 and6, friction wheel shaft 21 rotates substantially concentrically withfixedly positioned winder shaft 15. Since driving disk 27 and drivendisk 19 can be turned easily relatively to each other, the lateraldisplaceability of the axis of friction wheel shaft 21, relative to theaxis of winder shaft 15,

is independent of the radial position of slot 20 and of driving pin 28engaged therein, so that the winding mechanism can be started andstopped in any radial position of slot 20.

Depending on whether the thread supply on thread looper bobbin 13 is tobe supplemented without interruption of the sewing operation, or whetherthe operator wishes to supervise the winding operation, driving wheel 3can be disengaged from the work by means of release screw 4, or canremain engaged. The winding of looper thread bobbin 13 is effected in aknown manner.

Before bobbin 13 is completely filled with thread, the wound threadbegins to push sensing lever 32 away from bobbin 13. Release arm 34,with control pin 37, thus is slowly turned away from winder shaft 15until control pin 37 engages ramp 41 of leafspring 40. As soon as pin 37has reached ramp 41, leafspring 40 exerts, on control pin 37 of releasearm 34, a laterally directed force component, under whose action releasearm 34 returns rapidly into its rest position, representing in FIG. 6 inbroken lines. In the rest position, sensing lever 32 bears against theend of slot 35 in cover 2, and cover slot 35 completely in any of itspossible positions. As soon as leafspring 40 is no longer held away fromwinder arm 23 by control pin 37, it again exerts its pressure on thewinder arm and turns winder arm 23, against the tension of spring 31,about the axis of setscrew 29 which acts as a pivot and away fromdriving wheel 3 into the rest position, thus interrupting the windingprocess. V I

Naturally, the embodiment of the winding mechanism, as described can bemodified. Thus, for example, driving pin 28 could engage a sufficientlylarge bore in disk 19 instead of a slot therein. The transmission of themovement also could be effected by two driving cams engaging each other.It is further possible to design winder arm 23 and release arm 34 asrectilinearly moving slides instead of as pivotal levers. Naturally, thewinding mechanism embodying the invention also could be arranged on anyother part of the sewing machine, for example on the face of the sewingmachine arm facing the operator.

While a specific embodiment of the invention has been shown anddescribed in detail to illustrate the application of the principles ofthe invention, it will be understood that the invention may be embodiedotherwise without departing from such principles.

What is claimed is:

1. In a releasable winding mechanism for sewing machines of the typehaving a fixedly positioned winder shaft with a bobbin-receiving pinprotruding from the machine casing, a friction wheel, driving the windershaft, mounted on a friction wheel shaft separated from the winder shaftbut operatively connected with the winder shaft, and a driving wheel,with the friction wheel being arranged-to be operatively connected tothe driving wheel to operate the winding mechanism, the improvementcomprising, in combination, means mounting said friction wheel shaft fordisplacement of its axis laterally, relative to the axis of said fixedlypositioned winder shaft, between a winding mechanism operating positionand a rest position; and connection means constantly maintaining thedriving connection between said shafts throughout the range ofdisplacement of said friction wheel shaft between said operating andrest positions.

2. In a releasable winding mechanism for sewing machines, theimprovement claimed in claim 1, in which said mounting means for saidfriction wheel shaft comprises a carrier moving between a startingposition and a stopping position; and means spring biasing saidcarrierto both said positions.

3. In a releasable winding mechanism for sewing machines, theimprovement claimed in claim 2, a feeler protruding from the machinecasing and engaging the thread mounted on a bobbin, said feeler beingoperable to shift said carrier from one spring bias to the other springbias.

4. In a releasable winding mechanism for sewing machines, theimprovement claimed in claim 3, including a feeler carrier movablymounted in the machine casing and, in said operating position,maintaining a first spring out of engagement with said carrier of saidfriction wheel shaft; a second and weaker spring acting on said carrierof said friction wheel shaft in a direction opposite to said firstspring in said operating position; said feeler carrier, in the restposition, releasing said first spring to bias said carrier of saidfriction wheel shaft to the inoperative rest position and against thebias of said second spring.

5. In a releasable winding mechanism for sewing machines, theimprovement claimed in claim 1, in which said connection means comprisesa pin extending outwardly from one of said shafts and eccentric thereto,and a slot extending diametrically of the adjacent end of the othershaft and having said pin engaged therein.

6. In a releasable winding mechanism for sewing machines, theimprovement claimed in claim 1, in which said connection means comprisesa pin extending outwardly from one end of one of said shafts andeccentric thereto, and an eccentric bore in the facing end of the othershaft having a diameter larger than that of said pin and having said pinengaged therein.

7. In a releasable winding mechanism for sewing machines, theimprovement claimed in claim 1, in which said connection means comprisesrespective frontally rotating cams on said shafts and in engagement witheach other.

8. In a releasable winding mechanism for sewing machines, theimprovement claimed in claim 1, in which said connection means comprisesplastic composition members.

9. In a releasable winding mechanism for sewing machines, theimprovement claimed in claim 1, in which said shafis have facing ends;each cam having a disk secured to its facing end; one of said diskshaving a pin extending from its outer surface eccentrically thereof andthe other of said disks having a diametric slot engaging said pin.

10. In a releasable winding mechanism for sewing machines, theimprovement claimed in claim 4, in which said first spring comprises aleafspring having a free end engageable with said carrier for saidfriction wheel shaft, and having a ramp portion intermediate its ends;said feeler carrier having a pin at its free end engageable with saidfirst spring and being moved by said feeler to a position in which saidpin engages said ramp portion for biasing of said pin and said feelercarrier to said rest position, releasing said leafspring to engage saidcarrier for said friction wheel shaft.

In a releasable winding mechanism for sewing machines, the improvementclaimed in claim 4, in which said first spring comprises a leafspringhaving a free end engageable with said carrier for said friction wheelshaft, and having a ramp portion intermediate its ends; said feelercarrier having a pin at its free end engageable with said first springand being moved by said feeler to a position in which said pin engagessaid ramp portion for biasing of said pin and said feeler carrier tosaid rest position, releasing said leafspring to engage said carrier forsaid friction wheel shaft.

1. In a releasable winding mechanism for sewing machines of the typehaving a fixedly positioned winder shaft with a bobbinreceiving pinprotruding from the machine casing, a friction wheel, driving the windershaft, mounted on a friction wheel shaft separated from the winder shaftbut operatively connected with the winder shaft, and a driving wheel,with the friction wheel being arranged to be operatively connected tothe driving wheel to operate the winding mechanism, the improvementcomprising, in combination, means mounting said friction wheel shaft fordisplacement of its axis laterally, relative to the axis of said fixedlypositioned winder shaft, between a winding mechanism operating positionand a rest position; and connection means constantly maintaining thedriving connection between said shafts throughout the range ofdisplacement of said friction wheel shaft between said operating andrest positions.
 2. In a releasable winding mechanism for sewingmachines, the improvement claimed in claim 1, in which said mountingmeans for said friction wheel shaft comprises a carrier moving between astarting position and a stopping position; and means spring biasing saidcarrier to both said positions.
 3. In a releasable winding mechanism forsewing machines, the improvement claimed in claim 2, a feeler protrudingfrom the machine casing and engaging the thread mounted on a bobbin,said feeler being operable to shift said carrier from one spring bias tothe other spring bias.
 4. In a releasable winding mechanism for sewingmachines, the improvement claimed in claim 3, including a feeler carriermovably mounted in the machine casing and, in said operating position,maintaining a first spring out of engagement with said carrier of saidfriction wheel shaft; a second and weaker spring acting on said carrierof said friction wheel shaft in a direction opposite to said firstspring in said operating position; said feeler carrier, in the restposition, releasing said first spring to bias said carrier of saidfriction wheel shaft to the inoperative rest position and against thebias of said second spring.
 5. In a releasable winding mechanism forsewing machines, the improvement claimed in claim 1, in which saidconnection means comprises a pin extending outwardly from one of saidshafts and eccentric thereto, and a slot extending diametrically of theadjacent end of the other shaft and having said pin engaged therein. 6.In a releasable winding mechanism for sewing machines, the improvementclaimed in claim 1, in which said connection means comprises a pinextending outwardly from onE end of one of said shafts and eccentricthereto, and an eccentric bore in the facing end of the other shafthaving a diameter larger than that of said pin and having said pinengaged therein.
 7. In a releasable winding mechanism for sewingmachines, the improvement claimed in claim 1, in which said connectionmeans comprises respective frontally rotating cams on said shafts and inengagement with each other.
 8. In a releasable winding mechanism forsewing machines, the improvement claimed in claim 1, in which saidconnection means comprises plastic composition members.
 9. In areleasable winding mechanism for sewing machines, the improvementclaimed in claim 1, in which said shafts have facing ends; each camhaving a disk secured to its facing end; one of said disks having a pinextending from its outer surface eccentrically thereof and the other ofsaid disks having a diametric slot engaging said pin.
 10. In areleasable winding mechanism for sewing machines, the improvementclaimed in claim 4, in which said first spring comprises a leafspringhaving a free end engageable with said carrier for said friction wheelshaft, and having a ramp portion intermediate its ends; said feelercarrier having a pin at its free end engageable with said first springand being moved by said feeler to a position in which said pin engagessaid ramp portion for biasing of said pin and said feeler carrier tosaid rest position, releasing said leafspring to engage said carrier forsaid friction wheel shaft.